Heat exchanger

ABSTRACT

A heat exchanger includes an apparatus body, a motor, an air-exhaust fan casing, an air-supply fan casing, heat exchanging devices, an air-supply air-flow path, and an air-exhaust air-flow path. A first stacking pitch of heat transfer plates in the heat exchanging devices placed at positions other than that immediately after an outdoor suction port in the air-supply air-flow path and at positions other than that immediately after a indoor suction port in the air-exhaust air-flow path is smaller than a second stacking pitch of heat transfer plates in the heat exchanging devices immediately after the outdoor suction port in the air-supply air-flow path and immediately after the indoor suction port in the air-exhaust air-flow path.

TECHNICAL FIELD

The present invention relates to a heat exchanger for ventilating rooms.

BACKGROUND ART

FIG. 10 is a side structure view illustrating placement of a conventional heat exchanger. FIG. 11 is a bottom structure view illustrating placement of the heat exchanger.

As illustrated in FIGS. 10 and 11, apparatus body 114 includes inspection cover 101 on its lower surface and, further, includes, in its side surfaces, indoor suction port 102, indoor exhaust port 103, outdoor suction port 104, and outdoor exhaust port 105. Further, at a center portion of apparatus body 114, air-exhaust blade 106 and air-supply blade 107 are mounted on motor 108. Further, in apparatus body 114, air-exhaust fan casing 109 is provided outside of air-exhaust blade 106, and air-supply fan casing 110 is provided outside air-supply blade 107.

On the outer peripheral portions of air-exhaust fan casing 109 and air-supply fan casing 110, there are placed heat exchanging devices 111. Air-supply air-flow path 112 extends from outdoor suction port 104 to indoor exhaust port 103, through air-supply air-flow path structural plate 115, heat exchanging devices 111, air-supply blade 107, and exhaust pipe 117. On the other hand, air-exhaust air-flow path 113 extends from indoor suction port 102 to outdoor exhaust port 105, through air-exhaust air-flow path structural plate 116, heat exchanging devices 111, air-exhaust blade 106, and exhaust pipe 117 (refer to PTL 1, for example).

Heat exchanging devices 111 perform heat exchanging between air passing through air-exhaust air-flow path 113 and air passing through air-supply air-flow path 112. Specifically, heat exchanging devices 111 recover heat in the indoor space being subjected to air conditioning, from the air passing through air-exhaust air-flow path 113, and, using this heat, cool (or heat) the outdoor air passing through air-supply air-flow path 112, before this outdoor air is supplied to the inside of the room.

In order to increase the heat exchanging efficiency in heat exchanging devices 111, within the limited volume of apparatus body 114, the pitch of heat transfer plates stacked therein should be made smaller, and the number of the heat transfer plates in the heat exchanging devices 111 within the volume of apparatus body 114 should be increased, for attaining larger amounts of heat exchanges therein. With such a conventional heat exchanger, if stacking pitch of the heat transfer plates in the heat exchanging devices is made smaller, and the number of the heat transfer plates therein is made larger, within the limited volume of the apparatus body, this will increase the ventilation resistance inside the heat exchanging devices. This will increase the resistances in the air-flow paths (the ventilation resistances) inside the apparatus body, thereby inducing the problem of insufficient amounts of ventilation.

Citation List

Patent Literature

PTL 1: Unexamined Japanese Patent Publication No. 2006-349223

SUMMARY OF THE INVENTION

The present invention provides a heat exchanger including an apparatus body with a box shape which is provided, in its side surfaces, with an indoor suction port, an indoor exhaust port, an outdoor suction port, and an outdoor exhaust port; a motor on which an air-exhaust blade and an air-supply blade are mounted, at a center portion of the apparatus body; an air-exhaust fan casing provided outside the air-exhaust blade; an air-supply fan casing provided outside the air-supply blade; a plurality of heat exchanging devices which are placed on outer peripheral portions of the air-exhaust fan casing and the air-supply fan casing, each includes stacked heat transfer plates adapted to flow air streams of different temperatures along alternate ones of the heat transfer plates for exchanging heat; an air-supply air-flow path which extends from the outdoor suction port through the heat exchanging device and the air-supply blade and communicates with the indoor exhaust port; and an air-exhaust air-flow path which extends from the indoor suction port through the heat exchanging device and the air-exhaust blade and communicates with the outdoor exhaust port, wherein a first stacking pitch of the heat transfer plates in the heat exchanging devices placed at positions other than that immediately after the outdoor suction port in the air-supply air-flow path and at positions other than that immediately after the indoor suction port in the air-exhaust air-flow path is smaller than a second stacking pitch of the heat transfer plates in the heat exchanging devices immediately after the outdoor suction port in the air-supply air-flow path and immediately after the indoor suction port in the air-exhaust air-flow path.

As a result thereof, air inside the room and outdoor air are sucked through the indoor suction port and the outdoor suction port, respectively, and part of the sucked air flows through the insides of the heat exchanging devices including the heat transfer plates having the larger stacking pitch. Further, this air is sucked into the air-exhaust fan casing and the air-supply fan casing and, then, is discharged through the outdoor exhaust port and the indoor exhaust port. This prevents the ventilation resistance from being increased and, further, prevents the amount of ventilation from being insufficient.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a side structure view illustrating a heat exchanger according to a first exemplary embodiment of the present invention.

FIG. 2 is a bottom structure view of the heat exchanger.

FIG. 3A is a perspective view illustrating a stacking pitch of heat transfer plates in heat exchanging devices other than those immediately after an outdoor suction port and an indoor suction port, in the heat exchanger.

FIG. 3B is a perspective view illustrating a stacking pitch of heat transfer plates in heat exchanging devices immediately after the outdoor suction port and the indoor suction port, in the heat exchanger.

FIG. 3C is a perspective view illustrating a stacking pitch of heat transfer plates in heat exchanging devices which are positioned in the middle of an air-supply flow path and an air-exhaust flow path in the heat exchanger.

FIG. 4 is a perspective view illustrating sizes of heat exchanging devices in a stacking direction therein, in the heat exchanger.

FIG. 5 is a perspective view illustrating the structure of heat exchanging devices employing a mixture of different stacking pitches, in the heat exchanger.

FIG. 6 is a bottom structure view illustrating placement of bypass air-flow paths in a heat exchanger according to a second exemplary embodiment of the present invention.

FIG. 7 is a perspective view illustrating the structure of a bypass air-flow path in the heat exchanger.

FIG. 8 is a bottom structure view illustrating placement of bypass air-flow paths in the heat exchanger.

FIG. 9 is a bottom structure view illustrating placement of filters in bypass air-flow paths in the heat exchanger.

FIG. 10 is a side structure view illustrating placement of a conventional heat exchanger.

FIG. 11 is a bottom structure view illustrating placement of the heat exchanger.

DESCRIPTION OF EMBODIMENTS

Hereinafter, exemplary embodiments of the present invention will be described with reference to the accompanying drawings.

First Exemplary Embodiment

FIG. 1 is a side structure view illustrating a heat exchanger according to a first exemplary embodiment of the present invention, and FIG. 2 is a bottom structure view illustrating the heat exchanger. The heat exchanger includes apparatus body 5 having a box shape which is provided, in its side surfaces, with indoor suction port 1, indoor exhaust port 2, outdoor suction port 3, and outdoor exhaust port 4. At a center portion of apparatus body 5, air-exhaust blade 6 and air-supply blade 7 are mounted on motor 8. Air-exhaust fan casing 9 is provided outside air-exhaust blade 6, and air-supply fan casing 10 is provided outside air-supply blade 7. On the outer peripheral portions of air-exhaust fan casing 9 and air-supply fan casing 10, there are placed a plurality of heat exchanging devices 11.

In heat exchanging devices 11, there are heat transfer plates 20 laminated therein, and warm air and cold air at different temperatures alternately flow therethrough, so that heat transfer plates 20 perform heat exchanges therebetween. Further, inside apparatus body 5, there are formed air-supply air-flow path 12 and air-exhaust air-flow path 13. In this case, air-supply air-flow path 12 extends from outdoor suction port 3 through heat exchanging devices 11 and air-supply blade 7 to indoor exhaust port 2. Air-exhaust air-flow path 13 extends from indoor suction port 1 through heat exchanging devices 11 and air-exhaust blade 6 to outdoor exhaust port 4.

FIG. 3A is a perspective view illustrating a stacking pitch of the heat transfer plates in heat exchanging devices other than those immediately after the outdoor suction port and the indoor suction port, in the heat exchanger according to the first exemplary embodiment of the present invention. FIG. 3B is a perspective view illustrating a stacking pitch of the heat transfer plates in heat exchanging devices immediately after the outdoor suction port and the indoor suction port, in the heat exchanger. FIG. 3C is a perspective view illustrating a stacking pitch of the heat transfer plates in the heat exchanging devices which are positioned in the middle of the air-supply air-flow path and the air-exhaust air-flow path in the heat exchanger. As illustrated in FIG. 3A, the stacking pitch of heat transfer plates 20 in heat exchanging devices 11 other than those immediately after outdoor suction port 3 and indoor suction port 1 is defined as first stacking pitch 15 a. Further, as illustrated in FIG. 3B, the stacking pitch of heat transfer plates 20 in heat exchanging devices 11 a immediately after outdoor suction port 3 in air-supply air-flow path 12 and in heat exchanging devices lib immediately after indoor suction port 1 in air-exhaust air-flow path 13 is defined as second stacking pitch 15 b. In this case, second stacking pitch 15 b is made larger than first stacking pitch 15 a. Further, air-supply fan casing 10 and indoor exhaust port 2 are communicated with each other, and air-exhaust fan casing 9 and outdoor exhaust port 4 are communicated with each other, through respective exhaust pipes 14.

The heat exchanger having the aforementioned structure will be described, in terms of operations thereof. If motor 8 is operated, this causes air-exhaust blade 6 and air-supply blade 7 to rotate. Outdoor air is sucked through outdoor suction port 3 in air-supply air-flow path 12, and the outdoor air flows around the bottom surface in FIG. 1, namely to the bottom surfaces of heat exchanging devices 11, and further flows into heat exchanging devices 11. The outdoor air having passed through heat exchanging devices 11 is sucked into air-supply blade 7 and, thereafter, is supplied to the inside of the room through indoor exhaust port 2.

On the other hand, air inside the room is sucked through indoor suction port 1 in air-exhaust air-flow path 13, and the air inside the room flows around the top surface in FIG. 1, namely to the top surfaces of heat exchanging devices 11, and further flows into heat exchanging devices 11. The air having passed through heat exchanging devices 11 is sucked into air-exhaust blade 6 and, thereafter, is exhausted to the outdoor through outdoor exhaust port 4. At this time, heat exchanging devices 11 perform heat exchanges between air passing through air-supply air-flow path 12 and air passing through air-exhaust air-flow path 13.

In this case, air inside the room and outdoor air are sucked, through indoor suction port 1 and outdoor suction port 3, respectively. Part of the sucked air flow inside heat exchanging devices 11 a and lib including heat transfer plates 20 having second stacking pitch 15 b defined as larger. Further, part of the sucked air is sucked into air-exhaust fan casing 9 and air-supply fan casing 10 and, further, is discharged, through outdoor exhaust port 4 and indoor exhaust port 2.

Heat exchanging devices immediately after outdoor suction port 3 in air-supply air-flow path 12 and immediately after indoor suction port 1 in air-exhaust air-flow path 13 are adjacent to outdoor exhaust port 4 and indoor exhaust port 2, respectively. Therefore, the areas of the air-flow paths are minimized, thereby maximizing the ventilation resistances therein. To cope therewith, in the heat exchanger according to the first exemplary embodiment of the present invention, second stacking pitch 15 b of the heat transfer plates in heat exchanging devices 11 a and 11 b immediately after outdoor suction port 3 in air-supply air-flow path 12 and immediately after indoor suction port 1 of air-exhaust air-flow path 13 is locally made larger. As a result thereof, the ventilation resistances immediately after outdoor suction port 3 and immediately after indoor suction port 1 can be decreased, without largely degrading the heat exchanging efficiency.

Further, as illustrated in FIG. 3C, third stacking pitch 15 c of heat transfer plates 20 in heat exchanging devices 11 c which are positioned in the middle of air-supply air-flow path 12 and, also, in the middle of air-exhaust air-flow path 13 is made smaller than first stacking pitch 15 a.

Air inside the room and outdoor air is sucked through indoor suction port 1 and outdoor suction port 3, respectively, and part of the sucked air flows inside heat exchanging devices 11 c including heat transfer plates 20 having third stacking pitch 15 c defined as smaller. Further, part of the sucked air is sucked into air-exhaust fan casing 9 and air-supply fan casing 10 and is discharged, through outdoor exhaust port 4 and indoor exhaust port 2.

In the heat exchanger according to the first exemplary embodiment of the present invention, heat exchanging devices 11 c are spaced apart from outdoor suction port 3 in air-supply air-flow path 12 and from indoor suction port 1 in air-exhaust air-flow path 13 and are positioned in the middle of the respective air-flow paths. Heat exchanging devices 11 c are spaced apart from the minimum-distance air-flow path portions through which larger amounts of air flow from indoor suction port 1 toward air-exhaust fan casing 9 and from outdoor suction port 3 toward air-supply fan casing 10. Therefore, heat exchanging devices 11 c are less influenced by pressure losses induced by air flows. Accordingly, even though third stacking pitch 15 c of heat transfer plates 20 in heat exchanging devices 11 c is locally made smaller, the ventilation resistance in apparatus body 5 is prevented from being significantly increased. Further, these heat exchanging devices 11 c can attain larger amounts of heat exchanges than those by heat exchanging devices 11 placed immediately after outdoor suction port 3 and indoor suction port 1, thereby increasing the heat exchanging efficiency of the entire heat exchanger.

FIG. 4 is a perspective view illustrating sizes of heat exchanging devices in a stacking direction therein, in the heat exchanger according to the first exemplary embodiment of the present invention. Heat exchanging devices 11 are adapted such that their sizes in the direction of stacking pitch 15 of heat transfer plates 20 (sizes 16 in the stacking direction therein) are different from each other.

By doing this, with the plurality of heat exchanging devices 11 having different sizes 16 in the stacking direction of heat transfer plates 20, it is possible to clarify the positions at which heat exchanging devices 11 should be mounted, inside apparatus body 5, thereby preventing the occurrence of mistakes in mounting heat exchanging devices 11. This enables certainly mounting heat exchanging devices 11 during the fabrication of apparatus body 5 and, in addition thereto, enables improvement of the maintainability of heat exchanging devices 11 being used, during cleaning thereof, and the like.

FIG. 5 is a perspective view illustrating the structure of heat exchanging devices employing a mixture of different stacking pitches, in the heat exchanger according to the first exemplary embodiment of the present invention. Individual heat exchanging devices 11 placed on the outer peripheral portions of air-exhaust fan casing 9 and air-supply fan casing 10 may be formed to have a mixture of different stacking pitches 15.

By doing this, it is possible to adjust the heat exchanging efficiency and the ventilation resistance inside apparatus body 5, through heat exchanging devices 11 themselves, rather than through mixed placement of heat exchanging devices 11. Further, it is possible to mount heat exchanging devices 11 in apparatus body 5 without inducing mistakes. This enables certainly mounting heat exchanging devices 11 therein during the fabrication of apparatus body 5. Further, it is possible to improve the maintainability of heat exchanging devices 11 being used, during cleaning thereof, and the like.

Second Exemplary Embodiment

FIG. 6 is a bottom structure view illustrating placement of bypass air-flow paths in a heat exchanger according to a second exemplary embodiment of the present invention. FIG. 7 is a perspective view illustrating the structure of the bypass air-flow paths in the heat exchanger. In the second exemplary embodiment of the present invention, the same components as those of the first exemplary embodiment will be designated by the same reference marks and will not be described herein, in detail.

As illustrated in FIG. 6, in the heat exchanger according to the second exemplary embodiment of the present invention, a plurality of heat exchanging devices 11 are placed and, also, bypass air-flow paths 17 (FIG. 7) are placed, on the outer peripheral portions of air-exhaust fan casing 9 and air-supply fan casing 10. Specifically, part of air passing through air-supply air-flow path 12 is directly sucked into air-supply blade 7 through bypass air-flow paths 17 and, then, is directly supplied to the inside of the room. On the other hand, part of air passing through air-exhaust air-flow path 13 is directly sucked into air-exhaust blade 6 through bypass air-flow paths 17 and, then, is directly discharged to the outdoor.

In the heat exchanger according to the second exemplary embodiment of the present invention, heat exchanging devices 11 and bypass air-flow paths 17 are placed such that they are mixed therein. As a result thereof, by adjusting the positions at which bypass air-flow paths 17 are placed, it is possible to adjust the heat exchanging efficiency of the heat exchanger and the ventilation resistance inside apparatus body 5.

FIG. 8 is a bottom structure view illustrating placement of bypass air-flow paths in the heat exchanger according to the second exemplary embodiment of the present invention. In the heat exchanger, bypass air-flow paths 17 illustrated in FIG. 8 are placed on the entire outer peripheral portions of air-exhaust fan casing 9 and air-supply fan casing 10.

By doing this, it is possible to realize a blower capable of supplying air and exhausting air at the same time, while maintaining the shape of apparatus body 5.

FIG. 9 is a bottom structure view illustrating placement of filters in bypass air-flow paths in the heat exchanger according to the second exemplary embodiment of the present invention. In the heat exchanger, bypass air-flow paths 17 provided with filters 18 inside thereof are placed on the outer peripheral portions of air-exhaust fan casing 9 and air-supply fan casing 10.

By doing this, it is possible to purify air to be supplied to the inside of the room, without providing an additional filter outside apparatus body 5.

As filters 18 mounted in bypass air-flow paths 17, it is possible to employ dust filters and deodorization filters.

Further, as filters 18 mounted in bypass air-flow paths 17, it is possible to employ acoustical materials, which can reduce ventilation noises inside apparatus body 5.

INDUSTRIAL APPLICABILITY

It is possible to reduce the ventilation resistance inside the apparatus body without largely degrading the heat exchanging efficiency and, therefore, the present invention can be applied to applications of blowing apparatuses and the like which include heat exchangers required to have reduced ventilation resistances in the apparatus bodies in such a way as to maintain the sizes of the apparatus bodies.

REFERENCE MARKS IN THE DRAWINGS

-   1 Indoor suction port -   2 Indoor exhaust port -   3 Outdoor suction port -   4 Outdoor exhaust port -   5 Apparatus body -   6 Air-exhaust blade -   7 Air-supply blade -   8 Motor -   9 Air-exhaust fan casing -   10 Air-supply fan casing -   11, 11 a, 11 b, and 11 c Heat exchanging device -   12 Air-supply air-flow path -   13 Air-exhaust air-flow path -   14 Exhaust pipe -   15 Stacking pitch (of heat transfer plates) -   15 a First stacking pitch -   15 b Second stacking pitch -   15 c Third stacking pitch -   16 Size in the stacking direction -   17 Bypass air-flow path -   18 Filter -   20 Heat transfer plate 

1. A heat exchanger comprising: an apparatus body with a box shape which is provided, in its side surfaces, with an indoor suction port, an indoor exhaust port, an outdoor suction port and an outdoor exhaust port; a motor on which an air-exhaust blade and an air-supply blade are mounted, at a center portion of the apparatus body; an air-exhaust fan casing provided outside the air-exhaust blade; an air-supply fan casing provided outside the air-supply blade; a plurality of heat exchanging devices which are placed on outer peripheral portions of the air-exhaust fan casing and the air-supply fan casing, each of the plurality of heat exchanging devices includes stacked heat transfer plates adapted to flow air streams of different temperatures along alternate ones of the stacked heat transfer plates for exchanging heat; an air-supply air-flow path which extends from the outdoor suction port through one or more of the heat exchanging devices and the air-supply blade and communicates with the indoor exhaust port; and an air-exhaust air-flow path which extends from the indoor suction port through one or more of the heat exchanging devices and the air-exhaust blade and communicates with the outdoor exhaust port, wherein a first stacking pitch of the heat transfer plates in the heat exchanging devices placed at positions other than that immediately after the outdoor suction port in the air-supply air-flow path and at positions other than that immediately after the indoor suction port in the air-exhaust air-flow path is smaller than a second stacking pitch of the heat transfer plates in the heat exchanging devices immediately after the outdoor suction port in the air-supply air-flow path and immediately after the indoor suction port in the air-exhaust air-flow path.
 2. The heat exchanger according to claim 1, wherein the heat transfer plates in the heat exchanging devices which are positioned in the middle of the air-supply air-flow path and in the middle of the air-exhaust air-flow path have a third stacking pitch smaller than the first stacking pitch.
 3. The heat exchanger according to claim 1, wherein the heat exchanging devices have different sizes in a stacking direction of the heat transfer plates.
 4. The heat exchanger according to claim 1, wherein a mixture of different stacking pitches is provided in the plurality of heat exchanging devices placed on the outer peripheral portions of the air-exhaust fan casing and the air-supply fan casing.
 5. The heat exchanger according to claim 1, wherein some of the heat exchanging devices placed on the outer peripheral portions of the air-exhaust fan casing and the air-supply fan casing are replaced with a bypass air-flow path communicating the outdoor suction port with the air-supply blade and a bypass air-flow path communicating the indoor suction port with the air-exhaust blade.
 6. The heat exchanger according to claim 1, wherein all of the heat exchanging devices placed on the outer peripheral portions of the air-exhaust fan casing and the air-supply fan casing are replaced with a bypass air-flow path communicating the outdoor suction port with the air-supply blade and a bypass air-flow path communicating the indoor suction port with the air-exhaust blade.
 7. The heat exchanger according to claim 5, wherein a filter is provided within the bypass air-flow paths for purifying air delivered to an indoor space.
 8. The heat exchanger according to claim 7, wherein the filter comprises a dust filter.
 9. The heat exchanger according to claim 7, wherein the filter comprises a deodorization filter.
 10. The heat exchanger according to claim 5, wherein an acoustical material is provided within the bypass air-flow paths for reducing ventilation noises in the apparatus body.
 11. The heat exchanger according to claim 6, wherein a filter is provided within the bypass air-flow paths for purifying air delivered to an indoor space.
 12. The heat exchanger according to claim 11, wherein the filter comprises a dust filter.
 13. The heat exchanger according to claim 11, wherein the filter comprises a deodorization filter.
 14. The heat exchanger according to claim 6, wherein an acoustical material is provided within the bypass air-flow paths for reducing ventilation noises in the apparatus body.
 15. A heat exchanger comprising: a box-shaped apparatus body including an indoor suction port, an indoor exhaust port, an outdoor suction port and an outdoor exhaust port on side surfaces thereof; a motor including an air-exhaust blade and an air-supply blade mounted thereon, the motor disposed at a center portion of the apparatus body; an air-exhaust fan casing provided outside the air-exhaust blade; an air-supply fan casing provided outside the air-supply blade; a plurality of bypass air-flow paths on outer peripheral portions of the air-exhaust fan casing and the air-supply fan casing, each of the plurality of bypass air-flow paths includes stacked heat transfer plates adapted to flow air streams of different temperatures along alternate ones of the stacked heat transfer plates for exchanging heat; an air-supply air-flow path which extends from the outdoor suction port through one or more of the heat exchanging devices and the air-supply blade and communicates with the indoor exhaust port; and an air-exhaust air-flow path which extends from the indoor suction port through one or more of the heat exchanging devices and the air-exhaust blade and communicates with the outdoor exhaust port, wherein a first stacking pitch of the heat transfer plates in the heat exchanging devices placed at positions other than that immediately after the outdoor suction port in the air-supply air-flow path and at positions other than that immediately after the indoor suction port in the air-exhaust air-flow path is smaller than a second stacking pitch of the heat transfer plates in the heat exchanging devices immediately after the outdoor suction port in the air-supply air-flow path and immediately after the indoor suction port in the air-exhaust air-flow path. 